


So what does ‘Hentai’ mean anyway?

by Tangerine_Catnip



Category: Undertale (Video Game)
Genre: Adult Frisk, F/M, Female Frisk, Future Fic, Multi, OT3, POV Female Character, Telepathic Sex, Tentacle Sex, Tentacles, Threesome - F/M/M, fifteen years later
Language: English
Status: Completed
Published: 2015-10-10
Updated: 2015-10-10
Packaged: 2018-04-25 18:18:48
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,893
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/4971394
Author URL: https://archiveofourown.org/users/Tangerine_Catnip/pseuds/Tangerine_Catnip
Summary: <blockquote class="userstuff">
              <p>Frisk should really start reading the back of the boxes when she borrows DVD’s from Alphys.</p>
            </blockquote>





	So what does ‘Hentai’ mean anyway?

If you ask me, there's nothing quite like staying up all night and watching dumb shit with your friends. Especially if they're the kind of friends you can snuggle up to, kiss, and maybe have a quickie or two while the credits from the last movie roll.

It was my turn to pick out what we were watching tonight. But I didn't really have any ideas, so I swung by Alphys' house and grabbed some DVD's from her anime stash. Usually it was a pretty safe bet, since it would either be pretty good or bad enough to be funny. Plus Alpy and I share a love of magical girls so nine times out of ten I was glad I watched it.

I snap open the case and fish out the first of the DVD's in the set. Surprisingly, there's only two of them. I guess this series didn't last very long. Usually there's at least twenty episodes packed into the sets she buys.

I place the disk in the disk tray and it makes a little ping sound as it closes. Then walk back over to the couch and sit down between Papyrus and sans.

"So any warnings about what we're getting ourselves into here?" sans asks.

"Of course not!" I reply nudging him playfully on the shoulder. "That would ruin the whole surprise. Who knows, this could even be weirder than the last one."

"I'm not sure I could handle anything stranger than the weaponised undergarments." Papyrus mutters.

I grab a pillow from the floor and prop it against Papyrus's rib cage, giving it a little fluff before leaning against him.

"Oh come on, that was fantastic. And you even learned what pole dancing was. At this rate you'll be an expert on human culture in no time." I say.

"I don't know if I want to be an expert on _that_  kind of human culture."

"You sure about that?" I ask, leaning my head back so I can give him a knowing smirk. Papyrus blushes and wraps his arms around my chest.

The plasma screen lights up with a shot of a typical anime high school. I snatch up the remote and jam the play button down before the menu can finish its first play-through.

"If I had to guess. I'd say it's a monster of the week thing. The cover had some girls fighting an octopus." I explain.

"Aww… Poor octopus monster." Papyrus says.

"I'm sure it's nothing like any real monsters." I reassure him. Then I notice that sans is sitting very stiffly, and I can see his shoulders shaking just slightly, like he's trying and failing to hold back his laughter.

"sans?" I ask. Lifting up one of my legs and poking him in the ribs. I want to ask what's up, but the opening titles are already over and I need to start keeping my eyes on the screen so I don't miss any of the subtitles.

He looks over at me and I hold out my arms. Motioning for him to come over and cuddle with us. I just know he's up to something. But then, sans always seemed to give that impression.

He shifts over and as soon as he's within grabbing distance I pull him in and wrap my arms around his back. "Accidently" pressing his face into the squishy parts of my chest. Another useful trick I had learned from anime.

Sans took it in stride. He shifts onto his side and adjusts his 'pillow' little, getting comfortable. It tickles a little bit and I end up wiggling around, forcing sans to restart the whole process.

Eventually we settle and I turned my attention to the TV. I missed the first five minutes, but it looks like the action was just about to get started. The five female protagonists had just finished their transformation sequence, and were squaring off against the formless amalgamation of twisted limbs that was attacking their school.

At the moment, the monster had the upper hand and was using its appendages to stop the girls from attacking it. I expect that they'll have to use the power of friendship or something to turn the tide, but then, more of the tentacles start sliding under the girls' school uniforms.

The sound of ripping clothing and high pitched screaming fills the living room. I can't take my eyes off the screen. I knew about fan service, but I had never seen it get this intense before. I think about grabbing the remote and turning it off, but I'm really fucking curious about what happens next.

A second later I discover that my choice of swear word was a lot more apt than I intended.

Papyrus' hold around my middle tightens and I reflexively pass on the squeeze to sans. No one is saying anything. I guess that means they're as curious as I am.

I can feel my temperature rising. This is incredibly bizarre to watch, but damn if it isn't actually doing it for me. The dialogue is truly terrible, but it's really hard to care about what's being said when the camera was getting a close up shot right between her legs.

My heart rate is climbing and the casual cuddling of a few moments ago is replaced by desperate clinging. At least from Papyrus and me.

Finally, I can't take it anymore. I snatch up the remote from the floor and hammer the power button. The whole screen goes dark in a flash and I let out a long breath.

"ohhh man. That um… let's just… um… maybe, I should start looking these things up from now on, Hun?" I stutter. Glancing over my shoulder at Papyrus, then down at sans. Papyrus was apparently experiencing some kind of emotion halfway between acute embarrassment and utter confusion. While sans was taking the opportunity to muffle his laughter in my chest.

"Alright. Look, we'll just find something else to watch" I offer.

"Wasn't that bad." Sans says. He sat up, and took hold of one of my knees gently pushing it away until my legs were spread.

"At least, it sure looks like you enjoyed it." He added. Looking pointedly down at the crotch of my panties. The material was visibly soaked through.

"You know, Papyrus and I could recreate that for you." Sans offered.

"What… you mean like... the tentacles?" I asked, staring at him with my eyes as wide as they could go.

"Exactly."

"We can?" Papyrus asked. Leaning over my shoulder a bit.

"Course we can pap, it's magic right? It's not like we have to follow any rules of physics. If we can make ourselves dicks we can make practically anything." Sans replied with a shrug.

I look from one brother to the other. It only takes me a few seconds to reach my decision.

"Do it."

I wiggle in Papyrus' arms, tugging off my panties and pulling my bra straps off my shoulders. I expect him to let go so I can finish undressing, but Papyrus just clings tighter.

"Wait… Frisk, are you sure?" he asks. "Those girls in the movie didn't look like they were having much fun."

"Oh Papyrus, that's only pretend." I murmur. Lifting a hand to his face to rub his cheekbone reassuringly. "If I want you to stop I'll ask, okay? So don't worry about it."

"Speaking of-" sans added, taking hold of my other wrist. "If you need us to stop, hold two fingers up like this." he lifted his middle and pointer finger like he was making a peace sign. "Just in case your mouth is full."

I didn't realize I was blushing, but I can feel the heat in my cheeks now. I nod my agreement.

Sans sits back and I feel the air around us practically crackle as it fills with residual magical energy. I can't see the white glimmer of his eyes anymore. Only the left side was visible, glowing in gold then blue.

A magical construct flashes into existence like a lightning bolt. One second, it's not there, the next it is. It glows bright cobalt and looks like it's made of light. But when it starts to wrap itself around my lower leg it feels as warm and tangible as ever. It's perfectly smooth and a little bit slimy, raising goosebumps on my skin as it passes.

"So frisk. Do you want it exactly like what we saw?" sans asks.

"If you think you can make enough tentacles." I reply. What little common sense I have is a little concerned I might be taking on more than I can handle, but the rest of me is way too focused on the second blue tentacle binding my other leg to notice.

"I can if Pap helps."

We both look over at Papyrus. He still seems a little apprehensive, but more or less on board with our plan.

"Need any help with the magic?" Sans asks.

"Of course not." Papyrus replies. "Just give me a moment."

Papyrus gently releases his hold around my middle. Giving himself some distance so he can focus on the magic.

A shiver runs down my back as the atmosphere thickens even further. A new set of orange tentacles shimmers into view. They waste no time before wrapping my wrists and pulling my arms up above my head.

I cry out and suddenly the tentacles stop dead.

"Are you okay?" Papyrus asks.

"Yeah I'm fine. th-that was prefect." I reply. The tentacles are holding me up and I can't turn around. So I'll just have to hope he takes my words for it.

Even if they weren't color coded I could still tell which tentacles belonged to which brother. Sans' appendages started off narrow then got thicker and thicker until they were about four inches across. While Papyrus' where an even thickness from head to tip twice the length.

The blue tentacles lift my lower body up and the next thing I know I'm fully suspended. It's only a matter of inches off the couch, but that hardly matters. The two sets of tentacles work together to support my middle, wrapping around my tummy and breasts.

Sans sits down on the arm of the sofa, a cheeky smile on his face.

"Well that was surprisingly effective. We should try this next time you start misbehaving."

"You'll have to catch me first." I remind him. He nods his head in agreement, then glances over me to Papyrus.

"Let's start with the more difficult one then go from there." sans suggests.

"Right."

It's almost frightening how in sync Papyrus and sans can be when they're working towards the same goal. Especially when that goal involves me.

The tentacles around my legs pull in opposite directions. Spreading them as far apart as they can comfortably go.

One of the slender tendrils slithers down my lower back. I lean into the touch, pre-emptively relaxing as much as possible.

The probing tip of an orange tentacle slips between my butt cheeks. I giggle because it kind of tickles. It starts to press inside. The slick coating eases the process and Papyrus moves slowly so it only hurts a tiny bit.

I let out a shaky moan. Having things in my butt still feels weird, but I think I like it more and more every time I do it.

"Still doing okay?" Papyrus asks quietly.

"Yeah pap, that feels fantastic. I-I think I can take one more." I reply.

The second tentacle goes in easier now that I'm getting used to it. I gasp sharply it slips in next to the first. The pressure feels fantastic.

The two tentacles start moving, sliding in and out in unison very slowly.

Three new blue tentacles pop into existence and approach from the front. Sans is watching me closely, and I get the distinct impression the next few moments of my life are going to be extremely frustrating.

The tips of two of the tendrils spread my vaginal lips apart. Then the narrow tip of the third starts to tease. Rubbing against my clit then moving lower to brush against my entrance. Sans moves it like the tongue of a huge beast, giving each of my sweet spots just enough attention to be completely maddening.

My legs are shaking, even the tentacles suspending me can't hold tight enough to make it stop. I bit down on my bottom lip, but eventually I can't keep back the whimpers and gasps he's forcing from me.

"saaaaans.." I moan, trying to sound as sweet as possible. But I don't get a response.

"sans!" I force my head up. He's leaning back against the sofa. Almost like he's getting ready to take a nap. Frustration and anger boil up inside me. I know he's trying to get my goat, but I still fall for it.

"Sans! You better shove that fucking tentacle into me right fucking now or I-"

Before I can even finish my sentence something warm and thick surges forward and fills me up. Stars explode behind my eyes and for a second I can't even breathe.

The tentacle pushes again, but it's too thick to fit past that point. It's stretching me to my absolute limit. It starts to move in time with Papyrus' tentacles, but with a little jerk at the end of each thrust, to try to get more of it to go inside with every stroke.

"Is that what you wanted?" sans asks.

I can't find the breath to reply so I just nod.

The tentacles around my legs pull upwards and the next thing I know I'm hanging upside down and looking at Papyrus. His expression is absolutely adorable even the wrong way up.

"haa… Like what you're seeing?" I ask breathlessly.

"Yes!" Papyrus blurts. Unable to hold back his enthusiasm even a tiny bit.

I giggle. I feel really floaty, both from pleasure the blood rushing to my head.

"I'm not done yet. I still need one more." I remind him.

I open my mouth and stick out my tongue. Papyrus blinks at me. Then he seems to realize what I'm asking for. A final orange tentacle appears and prods my bottom lip gingerly, before sliding into my mouth.

Mercifully, I get turned right side up after that. I close my eyes, unable to truly believe what was happening to me.

Though to be fair, I also had a hard time believing the glowing magic dicks the first time I saw them.

I asked sans and Papyrus on multiple occasions how exactly they could derive pleasure from casting spells like that. The real answer involved some pretty complex monster biology that I still didn't quite understand. But the short version was that it had nothing to do with the spells.

Monsters, being almost completely comprised of soul, were naturally sympathetic to the emotions of those around them. Negative and positive. And the stronger the soul in question, the more drastically it could affect them.

Sans had once said that being around me mid-coitus was like standing near raging bonfire. Just with pleasure instead of heat.

But if they could feel even half if what I did right now it was a miracle they had enough concentration to keep moving their tentacles in sync. I couldn't even feel the sensations independently anymore. The tip of one of sans' tentacles was rubbing against my clit, rougher than was usually comfortable, but all my senses were too overloaded for it to hurt.

I was going to lose it any moment, and they could no doubt feel it. A pair of bony arms wrapped around my chest from behind. Then a second set joins in, this time from the front. I force one eye open. It's a complete mess of limbs and tentacles. But somehow it all seems to be working.

I want to speak. As soon as the desire hits me the tentacle in my mouth slides back. I take a long breath in forcing my voice out through sheer determination.

"sans.. Papyrus.." I just manage to get their names out before it hits me. I know they feel it too. Sans cums quietly but Papyrus moans loud enough for the two of them. I'm somewhere in between whimpering softly as the sensation peaks, then finally ebbs away.

The tentacles begin to unwind. Pulling away and vanishing as quickly as they had come. The second my arms are free I wrap one arm around each brother and I hug back with every ounce of strength I still have left.

The last traces of magic dissipate and sans' and Papyrus' eyes return to normal. They look just as exhausted as I feel, but they're lucky enough to not be covered and sweat and still slightly sticky between the thighs.

"So, uh… who's for skipping movie night and going straight to bed?" I murmur, my voice sounds rough. Probably from screaming too much.

I try to stand up and nearly fall over, sans and Papyrus each catch me by an arm.

"Or maybe sleep on the couch. That sounds good too." I amend.

"Sounds like a plan to me." sans agrees.

"Maybe just for a bit. Until you can walk again." Papyrus adds.

I smile and pause to give them both a kiss on the cheekbone.

"I love you guys."

**Author's Note:**

> i'm sorry that got a little strange at the end there. I have some very complicated ideas about exactly how monster courtship an sex work that i'm still working on.
> 
> also i'm not emotionally prepared to ALL CAPS Pap's dialog in a sex scene yet. maybe next time.


End file.
